1. Field of the Invention
The present invention relates to a lighting device incorporated into a liquid crystal module, for example, used for a display section of a laser printer.
2. Description of the Related Art
FIGS. 3 and 4 are views showing a liquid crystal module technique. According to this technique, the liquid crystal cells 2 and the light guide plate 3 are arranged in the bezel 1 and the lighting device 4 is arranged in a space formed between the light guide plate 3 and the edge plate portion la of the bezel 1 opposed to the light guide plate 3. The lighting device 4 illuminates the liquid crystal cells 2 from the back via the light guide plate 3. In this connection, reference numeral 5 is a polarizing plate, reference numeral 6 is a prism sheet, reference numeral 7 is a diffusion sheet, reference numeral 8 is a reflection sheet, reference numeral 9 is a flat flexible cable connected to the liquid crystal cells 2, and reference numeral 10 is a plug connected to each end portion of both lead wires 14.
The conventional technique of the lighting device 4 described above is disclosed in JP-A-2002-245838. Referring to FIGS. 5A to 5D, an example of the technique will be explained as follows. The lighting device 4 includes: a bottom plate 11a; a pair of side plates 11b which are bent at right angles from the bottom plate 11a; a lamp reflector 11 made of metal, the lateral cross section of which is a C-shape, having cutout portions 12 formed at both end portions of the bottom plate 11a; a straight-pipe-shaped light source 13 composed of a cold cathode ray tube arranged in the lamp reflector 11; a pair of lead wires 14 brazed to the straight-pipe-shaped light source 13; and a pair of sockets 15 made of elastic material such as rubber including a socket body 15A, the width h of which is substantially the same as the interval d between both side plates 11b of the lamp reflector 11, and including a branch portion 15B integrally protruding from the bottom face of the socket body 15A, the substantially L-shaped through-passage 16 being formed in a region from the inner end face of the socket body 15A to the inner face of the branch portion 15B, wherein the engagement protrusions 17 are integrally protruded from both sides of each socket, and the engagement holes 18 are formed on both side plates 11b of the lamp reflector 11 being opposed to the engagement protrusions 17.
The procedure of assembling the lighting device 4 will be explained below. The socket body 15A of each socket 15, which has covered a region from the end portion of each lead wire 14 to the end portion of the straight-pipe-shaped light source 13, is inserted into the lamp reflector 11 and each engagement protrusion is engaged with each engagement hole 18. In this way, the straight-pipe-shaped light source 13 can be positioned at a predetermined position in the lamp reflector 11.